Grease gun



April 25, 1933 R.' RAPELLIN GREAS E GUN Filed Dec. 9, 1951 ZV VENZ'B HEATER AF 'z. LIN

Patented Apr. 25, 1933 1 linnnv Barnum, or sANvGABRIEnrcaLiroRNIA l GRE'ASEGUN- Application IdDeCemher 9, vi931, Y vSerialV .7l9`8 82`1.1:

This invention 'relates to feedngmechanisms, -and" more particlarly to quickreturn feeding mechanisms wherein one `machine part may be advanced with respect "to :the

i other through V,the Vexpedient of a threaded mterengagement therebetweenwhich is 'capahle 'of being released to'gpeimit quick `return ofthe parts `to their-,initial V'relative position. l I Q i object of the,inventionis-theprovision of .afeeding mechanism,l which', while 'being capable yof practically universal application, is particularly designed as :means for forcibly .advancing 'a'plnnger in la cylinder. to eject the fluid or semitluid contents of the cylinder, such l construction being .commonly known .as a jgrease gun?? Accordinglthe device ofi the presentV invention lconstitutes an improvement .over'those ofiny prior Pat ents No. 1,724,616 and No.'1,724,617fissue.d August 13, 1929, and No.llOAQ .issued Juneie, 1931.. y Y .Y Y. v- 1A 'more detailed object oflthejpresent in- .25 .ventionisto provides. qnickre'lease feeding mechanism of improveddesign, comprising one or more threadedfmembers which may optionally .be "advanced Vvinto- .engagement with the feedscitew of the grease gun lor jretracted therefrom, Tand. meanscarried bythe closure cap for thejnpperend of the Vbarrel of the grease gunfor advaiicjlingothethreaded member or members fto'ltlhe screw' by rotaf tionof the closure'cap.

.Anotherob'ject is'to provide feeding mechanism of the general Vclasslindicated, wherein all :the voperative `parts whereby the threaded members are advanced 'and retracted," are contained inside the upper end iof thebarrel, therehyiavoiding fthe necessity of. providing apertures in thebarrel through which "the operating parts may extend andsfwhichare apt to permitfleaka'ge of the grease from the interior. 'of the gun, and "also providing la ubstantiallly smooth exterior-.surface on vthe entiregrease gun. A further object is tol materially simplify the construction and'todecrease the cost of manufacture vof. the grease Vun without im-A Pai'nsiS efsneyinany Wray-r j'lhe-invention'possesses other 'objects and advantageonsfeatures, 'some-of which, with those en'umeratechwvilljhelvsetforthin ithe Y following description of `the, inventionsipar'- tlcu'lar .embodiment/,whi'ohfis illustrated in thefdrawing "accompanying and apart offthe'fspecificationL 'Referringtofthe drawinggml FigL-"l"isa'longitudinal medial sectional View K of fa grease mechanism embo ying Athe 'principles ofthe present invention. 1 Portions of the `figure are broken away to redncefits size,"and the f feeding mechanism isl shown"with vfthe threaded members'engagingthe feedYsCIeW..

Fig. 2 is aview similar yto Fig.v "1, "but'showingthe threaded members ret'racted' from engagement with lthe feed screw'. A i

` ig. '3 is a transverse sectional View taken upon wenn@ +3 dfrig; 1v wah-'the direc.

tion of *View .,jasfpindicated, show-ing' 'the threaded 'members .engagvedv If `L Fig." 4 is 'a 'horizontal sectional viewi taken iipon the line P-'.41ct Figi.' 2, :with the direc-V tionof view `as indicated,"and showingfthev threaded "members disengaged. v n

Fig. is'a perspective view ofthe guide upon ahly mounted. 'I

which the #threaded membersare yslid-y ,"Broadiy Considered, thejaeyiee'jof the,

presentuinvention .comprises a 'feed screw longitudinally. "slidable .with respecty to .a suitable guide, fand preferably a V,plurality of threaded1.me'nfibers lor vsplit nutV ysections slidably mounted upon .the 'guide forfmovef ment Atoward or away from'thefeedscrew to. permit the nntparts optionallytfhev engaged therewith or-v disengaged therefrom; rotatable member 'encircles thef viv,feeiling screw,' and isl provided with aflangeoenlclio's'-w ing thenut'sections andhaving'a cam surf face whereby the nut sections maybe *ad vanced `into threaded engagement withthe Vfeedyscrew Vby turning "the said rotatable member'. Hence, when l.ther feeding mecha,r

nismjof the, present invention is embodied in a grease sum this rotatable member may convenientlybe employed 'as the .closure cap for the'upper .endfof thej'barrel; L s v f Q l Morejjspecically deSCIbed, .the feeding mechanism'of `the 'piesentl invention is indi? ido cated in its entirety at6, and is embodied in a grease gun 7, beingemployed therein as means for forcibly advancing a plunger 8 within a barrel 9 to eject the liquid or semiliquid contents of the barrel through a ,discharge orifice 11 in the lower closure cap 12 of the barrel 9. The plunger Sis carried by a Athreaded shaft or lfeed screw which is disposed coaxially ofthe barrel 9 andr extends slidably and rotatably through a hole 14 in a cap,.3f16;whichiserves as the closure for the upper end of the barrel 9.

The cap 16 is provided with an annular flange 17 which is threaded exteriorly and complementarily to threads`18 formedon the interior surface of the barrel 9 adjacent ythe upper end thereof, thereby permitting the cap 16 to'be mounted in theupper end of thebarrel` AHowever, when in operative position, the cap 16`4is not tightened against theend of the barrel, but is merely 'threaded into the barrel fai-.enoughftoinsurea suiiiciently tight joint between theV cap and the Vbarrel but to permit turningthe capwith respect to the barrel'through substantially a vquarter turn, so as to eifectladjustment of the split nut sections 21 and 22, Vas will be ldescribed hereinbelow.

`The nutsections 21 and 221are preferably 'in theV form` fof blocks or other suitably shapedv members slidably mounted upon t a guide plate or "disk'23` havingk threads 24' on itsperipheraledgeadapted to be engaged with theinterior threads 18ct the barrel 9 below the cap 1`6,.i'.e.',.theguideplate 23 is threadedfint'o the barrel beforethe lcap 16.

The` guide`23 is Vprovided with a central aperture 26,y through whichthestem o r feed screw 13 extend's,'and this aperture26 is considerably larger than the stem 13, soy that f thestein is freely reciprocable and rotatable withrespect tothe guide 23. Y

The stem 13 is'providedwiththreads 27, and complementary threads .28k are lformed y on the proximal faces of the blocks or split V' nut sections 21 and 22.) These blocks 21 and 22,; areadapted to Vbe slid radially inwards, so thatk their threads 28are Vbrought into engagement withthe threads 27 4of the-stem 13 uponrotation of the upperfclosure'cap 16,

To this'fendthe ilange 17 of the cap 16 is providedwith a camd surface 31 upon its inner face for each' of the blocks 21, 22. Each| cam 31 extends' for adistance of half a circle. The partsare so proportioned and arranged that when the blocks 21 and 22 are engaged by the' low portions 32`of the cam surfaces'` 31, i. e., `the portions of greatest radial distancefrom the stem13,`r the blocks d `21 yandv 22 are withdrawnfrom the kstem 13,

as illustrated upon Fig; 4, whereas the blocks 21v and 22 `are forced radially in. wards so thatl their' threads 28` engage'the threads 27 `of the steml 13 vwhen ,the blocks A are engaged bythe higlr'pointsi33iof the `cam surfaces 31, i. e., when the blocks are engaged by those portions of the cam surfaces which are at the least radial distance from the stem, as illustrated upon Fig. 3. Each of the cam surfaces 31 slopes gradually from the low point 32 to the high point 33, so thatV the blocks may be `forced radially inwards by turningthe cap 16 half a revolution with respect to the barrel 9.

The Vblocks 21v and 22 are prevented from YYturning'with the .cap- .16'1'by means of a pair of spaced upstanding guides 36, consisting of two blocks having plane vertical inner faces parallel to eachother and carried by th'ezp'late23, whichis secured to the barrel 9 by any suitable means such, .as ay locking screw 37, which holds the plate 23, guides 36, andblocks 21 and 22v from turning Y respect to the barrel.

' The blocks 21A and., 22,-' .continually urged loutwards''intof'contact with the Vcam surfaces 31.*byfineansof allspring 3 8, each end .39 of which engages the under surface of one of theblocks 21, 22." From the ends 39 horizontal portionsAl of thefspring` 38 extend transversely .withV respect lto fthe blocks, to one side ofthe stem 13, andy within the aperture 26 of the vplate 23.'. Thesehorizontaljsectionsf41 are connected integrally by an inverted, V-shaped portion 42'of the spring, which extends 4upwards from'l the aperture26. along -therouter facet, of 'one of the guides 36, lasbest shownfupon lFigs'3 andll, lthereby presenting a portionof the spring 38V which is accessible exteriorly of the grease gunf'after the' plate-. 23 and blocks 21 and 22 have been inserted intothe .barrel 9, and before ther cap;,16 has been placed in position'.- Thus Vitis possible to assemble the device with the spring 38properly connected to the blocks21 and 22.v A

By turning the cap 16.half Ya revolution `33ofthecam surfaces 31 into engagement with the blocks 21 22, thereby *causing the blocks to bevforcedinwards against the action of the spring 38: and into threaded engagement with the stem 13. Thereupon, the plunger 8 may be` moved, vlongitudinally of the barrel 9,by;rotating the stem,there by developing af mechanical advantage which permits., pressing. the plunger.- y8

against the contentsrof'jthef barrel 9 with its great force, although relatively 'little force is needed to rotate the stem 13.

It will' be observed that the device of the present invention differs from those disclosed in my aforesaid patents, inasmuch as the threaded members and the operating mechanism therefor, are contained entirely within the barrel 9 and upper closure cap 16. This avoids the necessity of providing any protruding portions on the exterior surface of the barrel, which makes the grease gun much easier to handle and much lless liable to become damaged through roughf` handling. Furthermore, the device of the present application is considerably less expensive than one of struction.

It is to be understood that the details of the invention as herein disclosed, are subject to alteration within the spirit or scope of the appended claims. l

I claim:

1. In a device tubular barrel, a'closure cap mounted adjacent one end of said barreland rotatable with respect thereto, a feed screw vextending slidably and rotatably through said cap, a pair of spaced guides rigid with said barrel and having opposed faces parallel to each other, a pair of threaded members slidable between said ried by said cap and having a pair of cams on its inner face engaging said threaded members, each cam extending a distance of half a circle, saidcam surfaces being adapted to advance said members to said screw when'said cap is turned half a revolution in one direction, and spring means for moving said members away from said screw when said cap is turned a half .revolution in the other direction. 7

' 2. In a device of the class described, ai'

tubular barrel, a closure cap mounted adjacent one end of said barrel and rotatable with respect thereto, a feed screw extending slidably and rotatably through. said cap, a guide rigid with said barrel, ka pair of threaded members slidable upon said guide, an annular flange carried by said cap and having a pair of cams on its inner face engaging said threaded members, each cam extending a distance lof half a circle, said cam surfaces being adapted to advance said members to engage said screw when said cap is turned half a revolution in one direction and spring means for moving said members away from said screw when said cap is turned a half revolution in the other direction.

In testimony whereof I have signed my name to this specification.

REN RAPELLIN.

more complicated conof the class described, a

guides, an annular ange car- 

